8 years. In the last chapter of the second volume I believe they show the ages (18 & 26)
Is it excusable since khalid is very mature?
In my opinion: No. Considering that despite the forced marriages of minors and their distaste towards their innocence being robbed, it was still normalized in actual history and in some countries today. So aside from irl situations, this age gap being so wrong, I guess you can just conclude for this manga ....it is fiction.
Sort of in the sense of: just because you enjoy reading thrillers with psychotic serial killers, does not mean you have to like the act of a human etc. being unalived irl.
Unfortunately, there are still those who won't get this. They believe that whatever you read, reflects your morality lol
Indeed. Whatever media, books or movies you consume should not make out a blueprint of your entire personality, yes it can influence it, but at the end of the day your choices are your own. So if this type of content is your tea, then it is so, as long as you are still able to differentiate between fiction and reality and can weigh your moral compass on it... then it's fine. Again this is my opinion. How you choose to see this is up to you.
how much is the age gap between them again?